The present invention generally relates to devices and methods for airway humidification. More particularly, this invention relates to personal humidification devices adapted to provide heated, gaseous (molecular) water-laden air to a patient.
In the past, numerous devices have been developed for use as personal humidification devices. These devices have been used, for example, to specifically target promoting pulmonary hygiene (mucous mobilization and/or clearance) and bronchial dilation in a patient. U.S. Pat. No. 4,773,410 and devices manufactured by the OECO Corporation and Gulfstream, various aerosol-producing or nebulization devices, continuous positive airway pressure (CPAP) and biphasic positive airway pressure (BIPAP) devices manufactured by Respironics, Res-med, Fisher Paykel and others, and Vapotherm “High Flow” technology devices have been devised and employed to do a similar job. Various steam humidifiers and “facial saunas” are also known personal devices that are intended for short-term use. Room, steam or warm mist humidifiers are also known for use as room humidifiers, though these devices are not adapted for personal use, in other words, to treat an individual as opposed to treating the environment within a room. The literature involving the medical use of gaseous (molecular) water, as opposed to aerosols containing a suspension of microdroplets of water, and findings relating to such uses is voluminous.
Room humidifiers are not personal humidifiers by definition and/or use. To be used as personal humidification, one would need to position oneself over the exhaust area for prolonged periods of time. It is physically difficult to do this and makes it very difficult or nearly impossible to do other things at the same time. Room humidifiers are simply designed for other than personal airway support.
Personal humidification devices of the types disclosed by U.S. Pat. No. 4,773,410 and manufactured by the OECO Corporation and Gulfstream are fairly large heavy machines and employ pumps to force humidified air through small bore tubing and simple nasal cannulas. These devices are uniquely capable of providing humidification effectively and efficiently to a sleeping subject. They can, but need not, produce noise levels that may disturb the user and others nearby. The devices can be expensive to own and operate, and may require professional cleaning and maintenance.
CPAP, BIPAP, high-flow and blow-over technology devices tend to be light, quiet, portable and provide varying levels of humidification. However, these rarely provide 100% water-saturated gases. In addition, few of these devices employ heated delivery and fewer employ monitored heated delivery. All of these devises use high-flow, fan-driven technologies that use large bore tubing and very uncomfortable and clumsy face masks or cannulas. While designed for sleep use, these devices are the least comfortable and cannot compete for comfort with smallbore heat-monitored pump-driven equipment. Consequently, many patients spend thousands of dollars on home equipment of this type that they dislike or will not use. True compliance to prescribed use can be inconsistent at best.
Personal heated humidifiers are well suited for humidifying an individual's airway. These devices are typically small, portable and relatively inexpensive. The shortcoming of this technology is that these devices are adapted for short-term use only. These devices are typically designed for fifteen to thirty minute uses, and require the user to bend over the device throughout this period of time. As with room humidifying steamers, other activities are nearly impossible while using personal humidifiers.
Aerosol devices are small, portable and usually inexpensive. The problem with these devices is that they employ sub-droplet liquid phase water (nongaseous or molecular), which means that this technology can transport viruses and bacteria to the user. In addition, the inhalation of nebulized water can cause broncho-spasm. This technology can be used to transport medication, but its uses for other treatment purposes have been questioned. Medically-supervised use may be advisable due to increased risk of broncho-spasms and potential for bacterial and/or viral inoculation, and therefore aerosol devices are not necessarily prescribed for personal humidification performed at home.
Accordingly, there is an ongoing need for personal humidification devices capable of being safely used by individuals at home that allow users some degree of freedom and comfort during use.